From owner-freebsd-net@FreeBSD.ORG  Sun Jun 22 15:32:34 2003
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id C2AEC37B401
	for <freebsd-net@freebsd.org>; Sun, 22 Jun 2003 15:32:34 -0700 (PDT)
Received: from angelica.unixdaemons.com (angelica.unixdaemons.com
	[209.148.64.135])
	by mx1.FreeBSD.org (Postfix) with ESMTP id E43F743FBF
	for <freebsd-net@freebsd.org>; Sun, 22 Jun 2003 15:32:33 -0700 (PDT)
	(envelope-from bmilekic@technokratis.com)
Received: from angelica.unixdaemons.com (bmilekic@localhost.unixdaemons.com
	[127.0.0.1])h5MMWVrd074176;	Sun, 22 Jun 2003 18:32:31 -0400 (EDT)
Received: (from bmilekic@localhost)
	by angelica.unixdaemons.com (8.12.9/8.12.1/Submit) id h5MMWVQ0074175;
	Sun, 22 Jun 2003 18:32:31 -0400 (EDT)
	(envelope-from bmilekic@technokratis.com)
X-Authentication-Warning: angelica.unixdaemons.com: bmilekic set sender to
	bmilekic@technokratis.com using -f
Date: Sun, 22 Jun 2003 18:32:31 -0400
From: Bosko Milekic <bmilekic@technokratis.com>
To: "George V. Neville-Neil" <gnn@neville-neil.com>
Message-ID: <20030622223231.GA72909@technokratis.com>
References: <877k7drj3h.wl@jchurch.neville-neil.com.neville-neil.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <877k7drj3h.wl@jchurch.neville-neil.com.neville-neil.com>
User-Agent: Mutt/1.4.1i
cc: freebsd-net@freebsd.org
Subject: Re: Zero Copy Sockets?
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 22 Jun 2003 22:32:35 -0000


On Sun, Jun 22, 2003 at 12:46:26PM -0700, George V. Neville-Neil wrote:
> Hi,
> 
> 	I'm reading over the internals of the network stack in
> 	-CURRENT and I'm wondering if the Zero Copy stuff is actually
> 	in use yet.
> 
> Thanks,
> George

  Yes.  But your driver needs to support it.  Currently, the only driver
  that does is if_ti in src/sys/pci/if_ti*.[ch]

  sendfile(2) is also zero-copy for the most part (for the file part).
  That's been in use for a long time.  src/sys/kern/uipc_syscalls.c

Regards,
-- 
Bosko Milekic  *  bmilekic@technokratis.com  *  bmilekic@FreeBSD.org
TECHNOkRATIS Consulting Services  *  http://www.technokratis.com/